This invention relates to improvements in a semiconductor luminescent display device having carrier injection electroluminescence.
There have been previously known semiconductor display devices of the type comprising a multiplicity of semiconductor display elements such as semiconductor luminescent diodes arranged in a matrix, each of the luminescent diodes including a pn junction through which a forward current flows to directly convert electrical energy to optical energy to display a figure or figures or a character or characters on the matrix. As compared with display devices employing discharge display tubes, fluorescent display tubes, incandescent filament display tubes, a plasma display panel, a cathode-ray tube, intrinsic electroluminescent display cells, or liquid crystal display elements, the above-mentioned type of semiconductor display devices have the following advantages:
(A) THE VOLTAGE INVOLVED IS LOW AND, FOR EXAMPLE, OF ABOUT ONE TO THREE VOLTS AND THE ADAPTABILITY OF SEMICONDUCTOR INTEGRATED CIRCUITS THERETO IS GOOD;
(B) THE RESPONSE SPEED IS HIGH. For example, a rise time to luminescence ranges from 10.sup.-8 to 10.sup.-6 second;
(C) THE RELIABILITY IS HIGH AND THE LIFETIME IS ON THE ORDER OF FROM 10.sup.5 TO 10.sup.6 HOURS;
(D) THE DEVICES ARE EASY TO MAKE IN SMALL SIZES AND ARE LIGHT; AND
(E) THE DEVICES HAVE HIGH VIBRATION AND SHOCK RESISTANCES AND ARE MECHANICALLY STRONG.
Thus such devices have been thought to be desirable for the purpose of displaying figures or characters.
The greater number of semiconductor display devices employing semiconductor luminescent diodes are of the seven segment type for the purpose of displaying figures. For the purpose of displaying characters, devices have been developed and produced which have matrices including seven rows and five columns, but it is still difficult put them to practical use. Many problems remain unsolved in the manufacturing thereof and also in the development of driving circuits for the semiconductor display devices. Conventional figure display devices have been able to be relatively simply assembled because the number of semiconductor luminescent diodes involved is small and the diodes include a common cathode electrode resulting in a small number of external terminals. However, upon displaying characters and more particularly complicated characters and/or patterns, it has been required to arrange semiconductor luminescent diodes forming a display device in a matrix, to group anode and cathode electrodes of the diodes by rows and columns respectively and to interconnect the grouped anode and cathode electrodes on a common surface respectively. This has resulted in the disadvantages that the electrical insulation between the adjacent diodes and the wiring of the diodes becomes complicated and a degree of integration is difficult to achieved.
Accordingly it is a general object of the present invention to eliminate the disadvantages of the prior art devices as above described.
It is an object of the present invention to provide an improved semiconductor luminescent display device comprising a plurality of gate controlled field effect type semiconductor luminescent elements formed into a novel monolithic structure.
It is another object of the present invention to provide a novel monolithic structure of a semiconductor luminescent display device which is light in weight, and small in size yet which is easily manufactured.
It is still another object of the present invention to provide an improved semiconductor luminescent display device having a novel monolithic structure which is easily controlled and which has high reliability.
It is a further object of the present invention to provide an improved semiconductor luminescent display of a novel monolithic structure having a low consumption of electrical power and a long lifetime.
It is another object of the present invention to provide an improved semiconductor luminescent display device having a novel monolithic structure having an extremely high response speed.